Regional cardiac wall motion from gated myocardial perfusion SPECT studies

A method for estimating regional epicardial and endocardial wall motion from gated myocardial perfusion SPECT studies has been developed. The method uses epicardial and endocardial boundaries determined from four long axis slices at each gate of the cardiac cycle. Epicardial and endocardial wall position at each time gate is computed with respect to stationary reference ellipsoids. Cardiac wall motion is computed along lines normal to the reference ellipsoids and is displayed in bullseye plots. An initial quantitative evaluation of the method was made using the beating heart from the dynamic mathematical cardiac torso (MCAT) phantom, with and without a 1.5 cm FWHM Gaussian blurring filter. Epicardial wall motion is generally well-estimated to within a fraction of a 3.56 mm voxel with and without the filter, although apical motion is overestimated with the Gaussian filter. Endocardial wall motion is underestimated by about two voxels, with and without the Gaussian filter. Regional cardiac wall motion also was analyzed for Tl-201 patient studies. Estimated wall motion was compared with nuclear medicine physician visual assessment of motion from gated long axis slices for example male and female studies. The estimated motion is consistent with the physician's readings of normal motion. Additional research is required for a comprehensive evaluation of the applicability of the method to patient studies with normal and abnormal wall motion.